1. Field of the Invention
This invention relates to starter drives generally, and more particularly to a dual start drive system for starting rotatable devices having large moments of inertia which must be overcome to bring them to operating speed such as gas turbines, electric rotors and the like.
2. Description of Prior Art
One way over-running clutches of the sprag type are well known in the prior art and have been used in starting mechanisms. It's also well known to provide several clutches in an operating mechanism which can be disengaged upon achieving a predetermined condition.
U.S. Pat. Nos. 2,077,253, to Nardone 3,251,442 to Aschauer, 4,305,002 to Mortensen and 4,418,289 to Mortensen all disclose two-state clutching mechanisms. However, none of these patents disclose the structure of the present invention including the co-axial arrangement of the two drive members and the output drive member of the starting device with the three members having inner race portions thereof disposed within a single outer race.